Seventy-two US Mk-5 atomic bombs entered service with the RAF at Honington, Marham and Waddington in 1958. Withdrawn from Honington and Waddington in 1961/2, they remained at Marham as its Valiants had been transferred to SACEUR. Weighing 3175 lb, the bomb was 11ft long and about 3ft 8in in diameter. With a composite plutonium/uranium 235 core, the yield was reportedly variable between 6 and 120 kilotons. When 24 weapons were established at Waddington, only one squadron (No 83) of Vulcans was established there and other V-force aircraft would have had to had been flown into Waddington from other bases to be armed with the Mk-5. This was contrary to the Bomber Command policy of dispersal as US law prevented the dispersal of these weapons. Three squadrons of Vulcan B1/B1As of unit establishment 8 each were established at Waddington by August 1961 and the 24 Waddington Mk-5s were withdrawn in April 1962.
© Courtesy Sandia National Laboratories.